New polyamide-polyamic acid block copolymers or flexible laminates - based on bi:phenyl-3,3,4,4-tetra:carboxylic acid di:anhydride and para-phenylenediamine

摘要

Block copolymers (I) with inherent viscosity 0.3-2.5 dl/g (0.5g (I) in 100 ml N-methylpyrrolidone (II)) comprise (A) repeating polyamic acid blocks contg. (A1) 100-50 mol.% repeating structural element of formula (1) (A2) 50-0 mol. % repeating structural element of formula (2) (B) repeating polyamide blocks contg. repeating structural element of formula (3) where mol. ratio of sum of no. of structural elements of formulae (1) and (2) to number of structural elements of formula (3) is more than 1, and corresp. cyclised polyamide-polyimide block copolymer derivs. (III). In the formulae, R is 1-6C alkyl, 1-4C alkoxy, halogen, Ph, or naphthyl; n is 0-4; R1 is tetravalent gp. of formula (i) or (ii), etc. these gps. opt. being substd. by 1 or more 1-4C alkyl or alkoxy, or halogen; X is direct bond, -CH2-, -CH(Me)2-, -C(CF3)2-, -O-, -S-, -CO-, -SO2-, -NHCO-, or =P(O)Ph; R2 is divalent gp. of formula (iii) or (iv), etc. these gps. opt being substd. by 1 or more 1-4C alkyl or alkoxy, or halogen; R3 is divalent gp. of formula (iii), (v), (vi) or (vii) these gps. opt. being substd. by 1 or more 1-4C alkyl or alkoxy, or halogen, or =-(CH2)n-(where n is 1-10). USE/ADVANTAGE - For prepn. of flexible laminates (claimed, partic. in electronics industry for prepn. of circuits, also matrix resins in fibre-reinfocred composites, paints, adhesives, coatings, films, mouldings. Solns. of (I) are storage-stable, (I) can be cyclised to (III) having relatively low thermal coefft. of expansion and high flexibility, coatings have good adhesion, partic. to metals.